Chain-drill.



Gr. 0. LEOPOLD.

CHAIN DRILL.

APPLICATION FILED APB..17. 1912.

1,033,712, Patented July 23, 1912.

COLUMBIA PLANoaRAI l-l c0 sHlNGToN, D. c.

GEORGE O. LEOPOLD, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO NORTHBROS.

IVIFG 00., OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYL-VANIA.

CHAIN -DRILL.

To all whom it may concern:

Be it known that I, GEORGE O. LEOPOLD, a citizen of the United States,residing in Philadelphia, Pennsylvania, have invented certainImprovements in Chain-Drills, of which the following is a specification.

My invention relates to certain improvements in drill mechanism, knownas chain drills, in which the drill tool or spindle is attached to thework through the medium of a chain; means being provided forautomatically feeding the tool to the work.

One object of my invention is to improve the construction of the feedingmechanism and to reduce the cost of manufacturing a tool of this type.

A further object of the'invention is to provide means for allowing theslack of the chain to be taken up by turning the spindle until a certainpressure is exerted, when the ratchet mechanism will be automaticallyapplied.

In the accompanying drawings :Figure 1, is a side view of my improvedchain drill; Fig. 2, is a sectional plan view on the line aa, Fig. 1;Fig. 3, is a sectional view on line b-b, Fig. 2; Fig. 4;, is a sectionalplan view on the line 0c, Fig. 3; Fig. 5, is a perspective viewillustrating one feature of the invention; and Figs. 6 and '7, are viewsillustrating modifications of the invention.

Referring to the drawings, 1 is a spindle having a squared end 2 adaptedto a brace, in the present instance, by which the spindle is turned.This spindle may form part of the breast drill, or may be coupled to itin any manner desired. The spindle extends through a carrier 3 fromwhich depends a rod 1. This rod extends through the opening in the chaingrip head 5, having a pin 6 at one end to which the chain 7 is attachedand a tapered slot 8 to which the free end of the chain may be attachedso that the chain, when it is passed over the work, may be attached tothis grip head in order to confine the tool to the work.

The grip head has a screw threaded opening and extending through thisopening is a threaded stem 9, having a ratchet wheel 10 at its upperend. The spindle 1 extends through the stem 9 and secured to its lowerend is a threaded section 11 on which the chuck 12 is mounted. Thisthreaded section Specification of Letters Patent.

Application filed April 17, 1912.

Patented July 23, 1912.

Serial No. 691,302.

forms part of the chuck, in the present instance.

26 is a collar resting on a shoulder formed by the threaded section 11and located between the collar and the lower end of the threaded stem isa series of anti-friction balls, Fig. 1. Mounted between the carrier andthe ratchet wheel 10 is a pawl piece 13, having an extension in which islocated the pawl 14, operated by a handle 15, and back of the pawl is aspring tending to force the tooth of the pawl into engagement with theratchet wheel. The tooth is beveled. at one side and can be turned tothe right or to.

the left so as to move the ratchet wheel in either direction and, whenmoved to the central position, as in Figs. 1 and 3, the pawl will beclear of the ratchet wheel. The pawl piece 13 has an enlarged opening 27in the center through which the spindle 1 extends and at each side ofthe pawl piece are slots 28 into which extend pins 16 on the carrier 3.

The spindle has a vertical slot 17 in which is mounted a roller 18. Thisroller bears against the side walls of the opening 27 in the pawl piece13 and as the spindle turns this roller acts as a cam to reciprocate thepawl piece 13 and rolls not only against the surface of the opening 27,but also in the slot 17 of the spindle; considerably reducing thefriction.

In orderto allow the tool to take up the slack in the chain beforeoperating the ratchet mechanism, I connect the spindle with the threadedstem 9 through a spring pin or ball 19, Fig. 3, which is mounted in anopening in the stem and back of the pin is a spring 20. The pin has arounded end and is adapted to a slot 21 in the stem 9 so that the stemis connected to the spindle until the slack in the chain is taken up andwhen the tension of the chain overcomes the pressure of the spring, thepin will be forced back independently of the screw stem.

If the pawl is set to feed the stem forward, then, at each revolution ofthe spindle, the screw stem will be fed forward a distance equal to atooth of the ratchet wheel.

In Figs. 6 and 7, I have shown a pawl piece 22 pivoted at 23 to a pin onthe carrier 3 and instead of the roll 18, illustrated in Fig. 5, a ball24: is used, adapted to a socket 25 in the spindle 1, as it will beunderstood that the ball may be substituted for the roller, but I preferthe roller as it has a more extended bearing surface.

#Vhen this invention is to be used, the drill or other tool is securedin the chuck and the chain is passed around the work; the free end ofthe chain being secured to the cross head 5. The spindle can be turnedby a brace; breast drill; or other turning device, and, as the spindleis turned, the screw stem 9 is turned with ittaking up the slack in thechain until the tension on the chain overcomes the pressure of thespring back of the pin 19, which looks the screw stem to the spindle;the pin being retracted and the spindle turned free of the stem. Thepawl can then be turned to engage the ratchet wheel to feed the stemforward as the drill acts upon the work. The stem 9 is fed forward onetooth of the ratchet wheel at each revolution of the spindle; the threadof the stem and the teeth of the ratchet wheel being so proportionedthat this feeding of the spindle forward will be about equal to theamount of the cut of the drilling tool; there being no likelihood of thedrill breaking down from over feeding.

As the spindle rotates, the roller carried by the spindle reciprocatesor vibrates the pawl piece; giving the necessary motion to the tool toallow it to turn the ratchet wheel the amount desired.

I claim:

1. The combination in a chain drill, of a spindle; a screw stem; a crosshead engaged by the screw stem; a chain secured to the cross head andengaging the work; a ratchet wheel on the end of the screw stem; a pawlpiece having an enlarged opening through which the screw stem passes; apawl carried by the pawl piece; and a roller carried by the spindle andarranged to engage the pawl piece so as to cause the pawl to feed thestem through the medium of the ratchet wheel.

2. The combination in a chain drill, of a spindle; a screw stem; a crosshead having an enlarged opening adapted to receive the screw stem; achain attached to the cross head and arranged to engage the work; aratchet wheel on the stem; a pawl piece; a

pawl carried thereby arranged to engage the ratchet wheel; said stemhaving a recess therein; a roller mounted in the recess; said pawl piecehaving an enlarged opening through which the stem extends; the rollerbearing against the wall of this opening in the pawl piece so that asthe stem is rotated, the pawl piece is actuated to rotate the ratchetwheel.

3. The combination of a spindle; a screw stem; a screw head on the screwstem; a chain connected to the cross head; a carrier through which thespindle extends; said carrier being connected to the cross head; pins onthe carrier; a pawl piece having an enlarged opening through which thestem extends; said pawl piece also being slotted at each side to receivethe pins of the carrier; a roller carried by the spindle and located inthe opening in the pawl piece so as to reciprocate the pawl piece whenthe spindle is turned; a pawl on the pawl piece; and a ratchet wheel onthe screw stem engaged by the pawl.

at. The combination-of a spindle; a carrier through which the spindleextends; a screw stem mounted on the spindle; a cross head having athreaded opening through which the stem extends; a rod connectmg thecarrier to the cross head; a chain secured to the.

cross head; means for turning the stem as the spindle is turned; ayielding pin on the spindle; the .stem being slotted to receive the endof the pin so that the screw stem will turn with the spindle to take upthe slack in the chain and when the slack is taken up, the spindle willturn independently of the stem.

5. The combination of a spindle having a recess therein; a rollermounted in the recess; a ratchet wheel on the spindle; a carrier; and apawl carried thereby; the roller acting upon the carrier to move thepawl to actuate the ratchet wheel.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

GEORGE O. LEOPOLD.

Witnesses:

Jos. H. KLEIN, WM. A. BARR.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). C.

